The term microelectromechanical system (MEMS) or micromechanical system/structure (MMS) is often used to refer to small integrated devices or systems that combine electrical and mechanical components. When focusing on the micromechanical part, the term “micromechanical system” may be used to describe small integrated devices or systems which comprise one or more micromechanical elements and possibly, but not necessarily, electrical components and/or electronic components.
Micromechanical systems may be used as, for example, actuators, transducers or sensors, e.g. pressure sensors. Pressure sensors are nowadays mass products in automobile electronics and consumer goods electronics. For many of these applications, systems are used in which the sensor is integrated in an application-specific integrated circuit (ASIC). For example, Infineon Technologies AG offers such a system as a side-airbag sensor.
In particular, the mechanically active elements of a micromechanical system may typically require relatively complex structures, such as recesses, beams, cantilevers, undercuts, cavities, etc. Possibly, a relatively high number of manufacturing steps are required. Furthermore, the process used for performing the micromechanical system may need to be compatible with possible subsequent manufacturing steps that are used for creating electrical and/or electronic components, for example.
Micromechanical systems or structures (MMS) may comprise deflectable structures such as membranes. A microelectromechanical structure (MEMS) may comprise one or more micromechanical structures whose deflectable structure may be deflected electrically (actuator). Alternatively or in addition, the MEMS may provide an electrical signal responsive to a deflection of the deflectable structure of the MMS (sensor). Movement of the deflected structure may lead to mechanical stress. Thus, there is a need to provide micromechanical structures with improved durability and/or deflection performance.